As a well known rotary stencil printing device, there is known the fully automated stencil printing device of a single printing drum type equipped with the function of making stencil printing master plates which comprises a printing drum internally provided with ink squeegee means for supplying printing ink and is adapted to be rotatively driven around an axial center line thereof, a stencil printing master plate feeding means disposed substantially laterally or horizontally opposite to the printing drum, and comprising a plate making portion for processing a stencil printing master plate sheet, and a stencil printing master plate sheet feeding portion for delivering the stencil printing master plate sheet to the outer circumferential surface of the printing drum, plate ejection means disposed substantially horizontally opposite to the printing drum for removing a stencil printing master plate mounted on the outer circumferential surface of the printing drum therefrom, a press roller disposed opposite to the outer circumferential surface of the printing drum for pressing printing paper against the outer circumferential surface of the printing drum, timing roller means for supplying printing paper to a nip defined between the printing drum and the press roller at an appropriate timing, and paper feed means for feeding printing paper to the timing roller means for supplying printing paper one sheet at a time. Such a fully automated stencil printing device of a single printing drum type equipped with the function of making stencil printing master plates is disclosed for instance in Japanese patent laid open (kokai) publication No. 59-96983.
When a full color printing or other multi color printing is attempted by using such a stencil printing device, it is necessary to superimpose picture images of different colors on printing paper by using a plurality of printing drums one after the other. Since the replacement of the printing drums has to be carried out manually, it is necessarily inefficient, and the registration involved in each step of printing the image of each color is So difficult that it is not possible for an inexperienced user to carry out such a printing process successfully.
On the other hand, it is conceivable to use a stencil printing device of a multi printing drum type which is provided with a plurality of printing drums for the printing of different colors so that the entire printing process can be carried out in a continuous manner by automatically conveying the printing paper from one printing drum to another. However, according to such a stencil printing device, since at least three, more preferably four printing drums are required in the case of full color printing, the printing device tends to be large in size. Further, since stencil printing master plate sheet feeding means and plate ejection means have to be equipped to each of the printing drums, and this necessity makes the size of the stencil printing device so large that the printing device cannot be made acceptable for most office uses.
To reduce the size of the stencil printing device of a multi printing drum type, it is conceivable to arrange the printing drums both vertically and laterally, but it would make the path of feeding printing paper so tortuous that the possibility of occurrence of paper jams would be unacceptably high, and the effort required to remove jammed paper may be substantial.